A nozzle is a device designed to control the direction or characteristics of a fluid flow as it exits an opening. Nozzles are commonly used in various applications, including spray bottles, fire hoses, and jet engines. They can change the speed, pressure, and shape of the fluid stream, making them essential for tasks like spraying liquids or directing exhaust gases. Nozzles come in different shapes and sizes, depending on their intended use. For example, a garden hose nozzle allows users to adjust the flow of water for different tasks, while a rocket nozzle helps to accelerate exhaust gases for propulsion. Understanding how nozzles work can improve efficiency in many fluid-related applications.